Camera Related Terminology

Here's some info to support your photography or film-making hobby.

1080i: A frame that is 1920 x 1080 pixels and 60 interlaced fields per second. Interlaced scanning systems create each frame by joining two interlaced fields of 539.9 lines each. 1080i produces 60 or 30 complete frames per second.

24P: Film’s native frame rate is 24 frames per second. 24P refers to the high definition format, the "P" meaning “progressive image scanning,” (in contrast to “interlaced scanning”).

480P: Lowest resolution scanning system of digital television. P stands for progressive meaning each complete frame is made up of 480 lines scanned one after the other.

720P: A frame that is 1280 x 720 pixels and 60 progressive frames per second. Progressive scanning system of digital television, also called High Definition Television, where each frame is made up of 720 lines scanned one after another.

Aliasing: The jagged, stepped lines that appear on computer generated images, due to pixilation.

Analog: A signal that fluctuates identically to the recorded stimulus.

Anti-Aliasing: The process which helps control the appearance of aliasing on computer generated images, usually including an alteration of background coloration and blurring.

Aperture Iris: The opening of the lens, measured in F-stops.

Aspect Ratio: measures width to height proportion of the television screen and all analog television pictures. Television is 4:3 and HDTV is 16:9.

Auto-focus: The camera focuses automatically on what it perceives to be the central object in a scene.

Auto-iris: The camera automatically controls the lens diaphragm (see iris).

Back light: Illumination behind the subject and opposite the camera. Often digitally manipulated in camcorders by adjusting exposure levels in the foreground of the image.

Barrel distortion: Curving distortion to vertical lines caused by wide angle lenses

Beam splitter: The internal optical prism setup that separates white light into the three primary colors: Red, Green, and Blue (RGB).

Bits: Binary digits.

Brightness: A color attribute that determines how light or how dark the color appears on a TV, or how much light the colors reflect.

Camcorder: A transportable camera with the video tape recorder built in or otherwise attached.

Cardioid: The heart-shaped sound pickup pattern of a unidirectional microphone.

Cassette: Audio or video device utilized for recording and playback of sampled material. A cassette contains two wheels and the tape medium rolled onto the two wheels.

CCD: Charge-Coupled Device, or light-sensitive integrated circuit that stores and displays image data by converting each pixel (picture element) into an electrical charge. The corresponding intensity of that charge directly relates to a specific color in the color spectrum.

Chrominance channel: A channel within a color camcorder which is responsible for a particular color. Usually, one chrominance channel will exist for each of the basic color signals: red, green, and blue.

Color bars: A standard color valuation for alignment of videotape recording.

Color compatibility: A descriptive quality used to indicate that a color scheme contains enough contrast in brightness for a monochrome (black and white) reproduction.

Color temperature: Measured in Kelvin degrees, this measurement refers to a light source’s relative redness or blueness.

Contrast ratio: A relationship indicative of the difference in light reflection (or brightness) of the brightest and the darkest spots of an image (i.e. a contrast ratio of 40:1 means that the brightest spot is forty times brighter than the darkest spot).

Cold: Usually used in reference to the camcorder’s accessory shoe, this descriptor refers to an object, or port, which doesn’t draw power from the camcorder.

Defocus: This process, or effect, occurs when the camera operator zooms in, alters the focus, and then, at the appropriate moment, restores the focus. This effect is used often in suspense films, psychological thrillers, etc.

Diffusion filter: A filter that, when attached to the front of the lens, gives the impression of diffused light--shadows are softer, and the image looks slightly out of focus.

Digital lens: A lens which, with an accompanying computer chip, is able to memorize and reproduce certain focal and zoom positions.

Digital versatile disc: Another name for DVD (digital video disc) which accounts for the recording ability of audio as well as video.

Digital8: Originally marketed, by Sony, as the bridge between digital video (DV) and analog tapes (8mm, video 8, Hi8), the Digital8 recording format uses DV compression to store data digitally on 8mm tape.

Digitize: To convert data into digital code (binary) from analog sources.

Disc: An optical storage unit that uses a laser to read and/or write to a computer.

Disk: A computer storage devise, either floppy (low-capacity, removable) or hard (large capacity, immovable) that stores data on concentric tracks.

Dropout: The effect of damage to or misalignment of video tape resulting in a loss of video signal, made manifest in colored or white glitches.

DVD: Abbreviation of digital video disc, storage unit of video and audio data necessitating a laser for reading and writing.

EFP: Abbreviation for electronic field production, usually referred to as field production, production shot for postproduction outside of the studio environment.

EIS: Abbreviation for electronic image stabilization, circuitry that attempts to counteract the negative effects of shaking the camera by electronically altering the image, oftentimes resulting in the increase of blur.

ENG: Abbreviation for electronic news gathering, refers to the process of gathering footage for immediate broadcast, using portable recording devises, usually for daily new purposes.

EVF: Abbreviation for electronic viewfinder, referring to a camcorder’s unit for monocular viewing, as opposed to the LCD for binocular viewing.

Field: Refers to half of the data contained in a picture frame, measured in lines. Two fields are necessary for one picture frame with data stored on alternating field lines.

Fluid Head: Mounting device for lightweight, portable, ENG/EFP cameras, which operates moving parts in fluid which allow for smooth camera movement.

Fluorescent: Term used to describe lamps that produce light through the illumination of phosphorous coating by gas-produced ultraviolet radiation.

Focal Length: Measured in millimeters or inches, this length refers to the distance between the center of the lens to the surface of the camera imaging device (CCD). Long focal lengths have small angles of view, while short focal lengths have wide angles of view.

Focus Crispness: Sharpness of images occurring when light beams converge once refracted by the lens.

Focus Ring: Section of cylinder located around the lens barrel of a camera, used to manually adjust focus.

Foot-candle: Abbreviated as fc, the foot-candle is a measurement of the amount of light falling upon an object at any given moment (illumination), called such as it refers to the amount of light falling on a square foot area located one foot away from a candle.

Frame: On video, the scanning of two fields (alternating every 1/60 second); on film, a single piece of celluloid on a filmstrip.

F-stop: Lens calibration measurement indicative of the iris opening, or aperture, measured in numbers of inverse proportion to aperture opening (i.e. large F-stop number equals small aperture opening)

Gain: For audio, the measurement of the amplification for audio signals; for video, measurement of the electronic amplification of the video signal, resulting in an increase of overall luminance.

High-Definition television, or HDTV: Operates with over twice as much detail as NTSC under either the 720P or 1080i scanning systems. 720P (720 progressive) uses 720 total lines scanned every 1/30 second. 1080i (1080 interlaced) uses two scanning fields of 539.5 lines each, interlaced with each other, one field recorded every 1/60 second.

High-Definition Television Camera: Cameras which use high-quality CCD devices to produce pictures of superior resolution, color quality, and contrast.

Hot: Usually used in reference to a camera’s accessory shoe, this term indicates that a camera feature, accessory, or port draws directly from the camera’s power source, battery or otherwise.

Hue: Describes the color itself (purple, orange, pink), as one of the three primary color attributes.

Interlaced Scanning: Scanning system in which two fields of lines are interlaced as alternating rows of lines. A beam reads each alternating field separately every 1/60 second, produces full frames (one reading of each field) every 1/60 second.

Iris: Adjustable lens opening that the allows light to pass through, also called lens diaphragm.

Jog Dial: Digital video jargon for the small joystick-like controllers often found on digital cameras and camcorders used to navigate through menus.

JPEG: a video compression process named after its developers, Joint Photographic Experts Group.

LANC: (Local Application Control Bus System) A protocol developed by Sony which enables video devices to be controlled externally, usually from a connected remote. Status information from these devices is also accessible. LANC is also known as Control-L.

Lens: Several planes of glass, or “lenses,” which can be focused onto a focal plane (on which sits a frame of celluloid film or a CCD) to create an image.
Lossless Compression: A form of compression that does not degrade the quality of the image.

Lossy compression: A form of compression in which image quality is degraded during compression.

Lux: A metric measurement of the amount of light or illumination on a subject

Microphone: An audio device used to create electronic signals out of sound vibrations. A microphone is a transducer, or quite simply, an energy converter.

Mini Disc: A small CD-like disc used for recording and distributing audio. Released by Sony in 1993, the format has decreased somewhat in status as MP3 and other encoded technologies have seen a dramatic rise in popularity.

MiniDV: A 1/4-inch “evaporated metal” digital tape format officially introduced for sale in 1995. In 1994, more than 50 companies and various manufacturers agreed on the MiniDV format. Sony was the first to develop a MiniDV camcorder, one year later.

ND Filters: Neutral Density filters can be attached to the lens of a camera to assist in preventing overexposure of an image. Prosumer camcorders have ND filters built in.

Pixel: Short for picture element. A single imaging unit that can be identified by a computer. Higher image quality results from more pixels.

Progressive Scan: A method of image scanning that processes image data one line of pixels at a time, creating frames composed of a single field (as opposed to interlaced scanning, which meshes two fields, each composed of alternating scanned lines, per frame).

Prosumer: Type of electronic product that straddles the Professional and Consumer market, or one who uses such a product.

RGB: Three main colors captured by a CCD imager: Red, Green, and Blue. Colors signals are then electronically mixed to create other colors in the spectrum.

Saturation: The amount of color information recorded to tape. The more color information available/recorded, the more saturated the image will appear. Saturation can be boosted electronically in postproduction, and prosumer camcorders offer menu options for manipulating saturation.

SD Card: Secure Digital cards are small memory devices that can be inserted into some electronic products, such as camcorders. They are used for storing digital media such as audio, video, or picture files.

Shutter: A shutter is opened and closed, allowing control over how long the focal plane is exposed to light. In a video camera, there is no physical shutter and instead the camcorder's CCD takes a sample of light for set length of time.

Shutter Speed: Measured in rotations per second, the number is specifies the rotating speed of the camera shutter, or in the case of digital video cameras, how quickly the CCD recognizes a new sample of light.
Signal-to-Noise Ratio: A ratio measuring the desired signal level to the level of unwanted image noise.

Solarization: Visual effect which converts a photographic image into a color negative 2; visual distortion (see first definition) of a camcorder’s LCD that occurs when the LCD is moved out of a direct line of sight.

Spot Focus: Feature on some camcorders that allows users to make precise adjustments to the focal image area by touching the LCD, or otherwise selecting a portion of the frame to be adjusted.

Spot Metering: Feature on some camcorders that allows users to adjust the exposure of an image by defining a spot on the LCD, either by touch or through the menu.

Telephoto Lens: A lens consisting of a narrow field of view resulting in a long focal length. Telephoto lenses are used to magnify subjects within that field of view.

Time Code: A numbering system that is encoded onto video tape recorded in hours, minutes, seconds, and frames. These numbers are then used in editing as a reference, appearing in this form: hh:mm:ss:ff.

Tripod: A three-legged stand used to stabilize a camcorder. Usually includes a movable “head” which the camcorder is affixed to which can be adjusted.

VHS: A half inch video tape format introduced in the 1976 by JVC (Victor Company of Japan).

White Balance: The correct calibration of a camera to record/display true white. All other colors are then calibrated based on that balanced white image.

Wide Angle: The maximum focal length of a lens

Windscreen: A faux fur or foam cover that can be slipped on to a microphone to block wind noises from being recorded. Also refers to a camera function that reduces wind noise digitally.

XLR Connecter: Balanced, three-pronged audio connectors used to connect mics to camcorders or to other types of recording equipment.

Zoom: To create movement on the Z axis of a 2-dimensional photographic image by shifting focal length from wide angle to telephoto, or vice versa.

Zoom Lens: A lens consisting of variable focal lengths

Zoom Range: Degree to which the focal length of a camcorder’s lens can be adjusted from wide angle to telephoto. Usually defined with a numerical ratio like 10:1 (telephoto : wide angle).